Airways

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oral airways
nasal airways
facemask
laryngeal mask
esophageal-tracheal combitube
endotracheal tubes

nasal airways
-helps prevent the tongue and epiglottis to fall back onto the posterior pharyngeal wall
-nasal airway creates an artificial airway for the passage of air through the nose leading into the larynx
-estimated length of nasal airways: distance from the nares to the meatus of the ear
-should not be placed in anticoagulated patients, children with prominent adenoids and basilar skull fractures

oral airways
-helps prevent the tongue and epiglottis to fall back onto the posterior pharyngeal wall
-oral airway creates an artificial airway for the passage of air through the mouth leading into the pharynx and later larynx
-adult airways generally come in 3 sizes: small 80mm, medium 90 mm and large 100mm

FACE MASK
-creating an airtight seal around the patients face the face mask can facilitate delivery of air/oxygen and anesthetic agents
-recognition of vomiting and exhalation of expired air can be noticed using a transparent face mask
-retaining hooks on the face mask allow for an attachment of headstrap leaving hands free management of the airway
-improper positioning of the face mask can lead to a substantial air leak
-airleak from improper positioning can be evidenced by a continual deflation of the resevoir bag while the PRV is open
-obstructed airway may be observed with high pressure during attempts of ventilation with little or no chest movement
-facemask and face strap positions should be changed frequently to prevent ischemic injury
-corneal abrasions must be avoided by not creating pressure on the eyes while mask ventilating the patient

LARYNGEAL MASK AIRWAY
-commonly used in replace of a face mask or endotracheal tube
-allows for delivery of oxygen/air and anesthetic gases to be delivered from the breathing to circuit to the patient's airway
-facilitates in ventilation especially in a difficult venitlation patient and also helps in the placement of an ETT
-partially protects the larynx from pharyngeal secretions but not gastric contents if regurgitation were to occur
-should generally be in place and not removed until the patient has intact airway reflexes
contraindications for LMA use:
-pharyngeal pathology ex. pharyngeal abcess
-patients considered full stomachs (ex. trauma, pregnancy, SBO, diabetic gastroparesis)
-patients with low pulmonary compliance who require increased peak inspiratory pressures (ex. obese patients)
-controversy still remains wether it is to be avoided or beneficial in bronchospastic prone patients

ESOPHAGEAL-TRACHEAL COMBITUBE
-consists of two fused tubes of differing lengths
-longer blue tube has an occluded distal tip with various side ports for air entry into the larynx
-shorter clear tube has a patent distal end and no side ports therefore air entry into the larynx occurs at the tip of the tube
-generally inserted blindly and then both cuffs are inflated
-95% of the time the distal lumen usually lies in the esophagus
-distal lumen intubating the esophagus requires ventilation through side ports of the longer blue tube into the larynx
-if the combitube enters into the trachea then ventilation can be performed through the shorter clear tube through distal opening
-combitube may be more advantageous over an LMA because it allows for better protection from aspiration of gastric contents

ENDOTRACHEAL TUBES
-allows for most control of oxygenation and ventilation
-allows for delivery of oxygen/air anesthetic gases into the trachea from the breathing circuits
-usually made from polyvinyl chloride
-I.T = 'implant-tested' to make sure there is no toxicity
-inserting a stylet allows for rigidity and maintained shape of the ETT
-beveled tip at the distal end of the ETT allows for better visualization while passing through the tip past the vocal cords
-murphy eye decreases the risk of occlusion in case the distal end of the ETT abuts the walls of the carina
-size of ETT are generally measure by internal diameter (I.D)
-deciding on ETT size is a balance between decreased airflow resistance of larger size and decreased airway trauma with smaller
-ETT cuffs allow for postive pressure ventilation and helps to prevent aspiration in case of gastric regurgitation occurs
-two major types of cuffs: high pressure (low volume) cuffs and low pressure (high volume) cuffs
-ischemic damage to the tracheal mucosa is more associated with a high pressure (low volume) cuff
-sore throat, aspiration, spontaneous extubation and more difficult insertion are associated with low pressure (high volume) cuffs
-generally low pressure (high volume) cuffs are more commonly used

flexible, spiral-wound, wire reinforced ETT: resist kinking
microlaryngeal ETT
RAE preformed ETT
double lumen ETT

armored tubes
-generally useful in head and neck surgery and procedures involving the prone position
-if the armored tube becomes kinked (ex.biting the tube), the occlusion will remain and the ETT replacement will be indicated